Count on some calculus. Calculus may sound intimidating, but it's an amazing tool chest for understanding both the behavior of numbers and the world around you.Calculus will teach you about functions and about limits. You'll see the behavior or a number of useful functions including e^x and logarithmic functions.You'll also learn how to calculate and work with derivatives. A first derivative gives you information based on the slope of a tangent line to an equation. For instance, a derivative tells you the rate at which something is changing in a non-linear situation. A second derivative will tell you whether a function is increasing or decreasing along a certain interval so that you can determine the concavity of a function.Integrals will teach you how to calculate the area beneath a curve as well as volume.High school calculus usually ends with sequences and series. Although students won't see many applications for series, they are important to people who go on to study differential equations.Calculus is still only the beginning for some. If you are considering a career with a high involvement of math and science, like an engineer, try going a bit farther!